Catalyst-aided chemical processing method

ABSTRACT

A catalyst-aided chemical processing method is a novel processing method having a high processing efficiency and suited for processing in a space wavelength range of not less than several tens of μm. The catalyst-aided chemical processing method comprises: immersing a workpiece in a processing solution in which a halogen-containing molecule is dissolved, said workpiece normally being insoluble in said processing solution; and bringing a platinum, gold or ceramic solid catalyst close to or into contact with a processing surface of the workpiece, thereby processing the workpiece through dissolution in the processing solution of a halogenide produced by chemical reaction between a halogen radical generated at the surface of the catalyst and a surface atom of the workpiece.

This application is a Divisional of U.S. application Ser. No.12/832,194, filed Jul. 8, 2010 now abandoned, which is a Divisional ofU.S. application Ser. No. 11/401,315, filed Apr. 11, 2006, now U.S. Pat.No. 7,776,228.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a catalyst-aided chemical processingmethod, and more particularly to a catalyst-aided chemical processingmethod for processing a workpiece by using an active species which isgenerated by dissociating a molecule in a processing solution with acatalyst.

2. Description of the Related Art

Mechanical processing methods have long been used in various fields. Amechanical polishing method, for example, involves pressing a toolagainst a surface to be processed so as to process the surface bycreating defects in the surface and taking away surface atoms through amechanical action. Such a mechanical polishing method causes damage to acrystal lattice and, in addition, can hardly provide a high-precisionprocessed surface. In order to process a workpiece with high precision,it is necessary to use a chemical processing method which can processthe workpiece without producing a lattice defect in it.

A processing method called EEM (elastic emission machining) is knownwhich involves allowing a suspension of ultrafine powder to flow along aprocessing surface of a workpiece so as to bring the ultrafine powderinto contact with the processing surface, without applying a substantialload on it, and processes the processing surface by removing surfaceatoms of the processing surface on the order of atomic unit through aninteraction (sort of chemical bonding) between the ultrafine powder andthe processing surface (Japanese Patent Laid-Open Publication No.2000-167770 and Japanese Patent Publications Nos. 2-25745, 7-16870 and6-44989). Further, plasma CVM (chemical vaporization machining) has beenproposed which is a processing method comprising supplying a neutralradical, which has been produced by decomposition of a reactive gascaused by high-voltage application to a processing electrode, to aprocessing surface of a workpiece while moving the processing electroderelative to the processing surface, thereby processing the processingsurface through vaporization and removal of a volatile compound producedby a radical reaction between the neutral radical and an atom or amolecule of the processing surface (Japanese Patent No. 2962583). Uponthe processing, the processing time is numerically controlled based onprocessing time-processing amount correlation data, determined by thetype of the reactive gas and the material of the workpiece, and also oncoordinate data regarding a pre-processing surface and an intendedpost-processing surface and according to the coordinate difference. Ahigh-efficiency processing method, utilizing a high-density radicalreaction, has also been proposed which involves rotating a rotaryelectrode at a high speed to bring in a gas with a surface of therotating electrode, thereby creating a flow of the gas that passesthrough a processing gap (Japanese Patent No. 3069271).

The above-described EEM and plasma CVM are both excellent chemicalprocessing methods. The EEM method can provide a flat processed surfaceat an atomic level. High-efficient processing, comparable to mechanicalprocessing, can be effected with high precision by plasma CVM.

As will be appreciated from the processing principle of EEM, it ispossible with EEM to obtain a very flat processed surface for ahigh-frequency space wavelength. In EEM, fine particles are supplied byultrapure water to a processing surface of a workpiece, and processingprogresses through chemical bonding between atoms of surfaces of thefine particles and atoms of the processing surface. The surfaces of thefine particles constitute a very flat surface and the flat surface isconsidered to be transferred as a base surface to the processingsurface. It is therefore possible to obtain a flat processed surface ofan atomic order without disordering atomic arrangement. Because of theprocessing principle, however, it is difficult with EEM to flatten aprocessing surface for a space wavelength range of not less than severaltens of μm.

Because of the use of an active radical, plasma CVM is ahighly-effective processing method. Plasma CVM utilizes a chemicalreaction between a neutral radical in plasma and a surface of aworkpiece. In particular, processing is carried out by generatinghigh-density plasma in a high-pressure atmosphere of 1 atom and causinga neutral radical generated in the plasma to act on an atom of a surfaceof a workpiece to convert the atom into a volatile substance. Plasma CVMcan thus process a processing surface with a high processing efficiency,comparable to conventional mechanical processing, without entailingdisorder of atomic arrangement in the processing surface. With no basesurface, however, the processing is likely to be affected by the planeindex of the processing surface.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve the above problems inthe prior art and provide a novel processing method having a highprocessing efficiency and suited for processing in a space wavelengthrange of not less than several tens of μm. The processing method shouldbe a chemical processing method from a crystallographical viewpoint,because a mechanical processing method entails a production with alattice defect in a surface of a workpiece, which makes it difficult toprocess the workpiece with high precision. The present invention,therefore, utilizes the well-known principle of transferring a basesurface through a chemical reaction. It is also important that a basesurface not change, because if a base surface changes, the processingsurface of a workpiece also changes with the progress of processing.Accordingly, the present invention offers a catalyst-aided chemicalprocessing method which entails no change of base surface and is capableof chemical reaction through a catalytic action.

In order to achieve the above object, the present invention provides acatalyst-aided chemical processing method comprising: immersing aworkpiece in a processing solution in which a halogen-containingmolecule is dissolved, said workpiece normally being insoluble in saidprocessing solution; and bringing a platinum, gold or ceramic solidcatalyst close to or into contact with a processing surface of theworkpiece, thereby processing the workpiece through dissolution in theprocessing solution of a halogenide produced by chemical reactionbetween a halogen radical generated at the surface of the catalyst and asurface atom of the workpiece.

Preferably, the halogen-containing molecule is hydrogen halide, and thehydrogen halide is dissociated at the surface of the catalyst togenerate the halogen radical. The hydrogen halide preferably is hydrogenfluoride or hydrogen chloride.

In a preferred aspect of the present invention, the catalyst has orprovides a processing base surface, and the configuration or pattern ofthe base surface is transferred to the processing surface of theworkpiece.

In a preferred aspect of the present invention, the processing iscarried out by using a processing tool comprising a synthetic resin baseand a plating or coating film of said catalyst provided on a surface ofthe synthetic resin base.

In a preferred aspect of the present invention, the processing iscarried out by using a processing tool comprising a mixture of asynthetic resin base and powder of said catalyst, with part of thecatalyst powder being exposed on a surface of the synthetic resin base.

In a preferred aspect of the present invention, the processing iscarried out by using either a processing tool comprising a non-wovenfabric and powder of said catalyst carried in the interstices of thenon-woven fabric or a processing tool comprising a non-woven fabriccomposed of fibers plated or coated with said catalyst.

In a preferred aspect of the present invention, the processing iscarried out by dispersing said catalyst in a fine powder form in theprocessing solution and supplying the fine catalyst powder to theprocessing surface of the workpiece by a flow of the processingsolution.

The catalyst-aided chemical processing method of the present inventionthus uses a platinum, gold or ceramic solid catalyst for a processingbase surface, and processes a workpiece by generating a halogen radicalthrough dissociation of a halogen-containing molecule, dissolved in theprocessing solution, at the surface of the catalyst, and dissolving inthe processing solution a halogenide produced by chemical reactionbetween the halogen radical and a surface atom of the workpiece close toor in contact with the catalyst. A hydrogen halide acid, in which aworkpiece normally is insoluble, may therefore be used as the processingsolution. The halogen radical, generated at the surface of the catalyst,rapidly becomes inactive as it leaves the surface of the catalyst. Thus,the halogen radical exists only on or in the vicinity of the catalystsurface which serves as a base surface, whereby processing can beeffected under spatially-controlled conditions.

High-efficient processing is possible when using, as the hydrogenhalide, hydrogen fluoride or hydrogen chloride which contains fluorineor chlorine having a strong chemical reactivity. The precision of aprocessed surface depends on the precision of a catalyst surface whichserves as a base surface. Accordingly, a surface of a workpiece can beprocessed with high precision by preparing a high-precision catalystsurface. When a pattern is formed with high precision on the catalystsurface, the pattern can be transferred to the surface of the workpiece,with a raised portion of the pattern being transferred to form a recessin the workpiece surface.

The processing may be carried out by using, for example, a processingtool comprising a synthetic resin base and a plating or coating film ofthe catalyst provided on a surface of the synthetic resin base, aprocessing tool comprising a mixture of a synthetic resin base andpowder of the catalyst, with part of the catalyst powder being exposedon a surface of the synthetic resin base, a processing tool comprising anon-woven fabric and powder of the catalyst carried in the intersticesof the non-woven fabric, or a processing tool comprising a non-wovenfabric composed of fibers plated or coated with the catalyst. The use ofsuch a processing tool can provide a processed surface having thesimilar configuration to that provided by conventional polishing orlapping.

The processing may also be carried out by dispersing the catalyst in theform of fine powder in the processing solution and supplying thecatalyst powder to a processing surface of a workpiece by a flow of theprocessing solution. This manner of processing can provide ahigh-precision processed surface comparable to that provided by EEM.

The catalyst-aided chemical processing method of the present invention,because of being a chemical processing utilizing a processing basesurface, is suited for processing in a space wavelength range of notless than several tens of μm, which processing has been difficult withEEM or plasma CVM. The present processing method can process SiC, ofcourse, and can also process with high precision those materials such asSiC, ceramics, sapphire and ruby which have hitherto been difficult toprocess, and could therefore be used in the field of semiconductormanufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A through 1C are conceptual diagrams illustrating thecatalyst-aided chemical processing method of the present invention, FIG.1A showing a catalyst and a processing surface of a workpiece, thecatalyst having been brought close to or into contact with theprocessing surface, FIG. 1B illustrating generation of an active Fradical by dissociation of an HF molecule in an HF solution into H and Fin the vicinity of the catalyst, and FIG. 1C illustrating progress ofprocessing through chemical reaction between the F radical and theprocessing surface;

FIG. 2A is a schematic perspective view of a processing apparatus forbasic experiment, and FIG. 2B is an enlarged perspective view of themain portion of the processing apparatus;

FIG. 3A shows the surface irregularities distribution including aring-shaped processing mark observed under a Michelson-typephase-shifting interference microscope, and FIG. 3B shows a linedistribution along one diameter of the processing mark.

FIGS. 4A through 4D show the results of observation of an SiC wafersurface before processing, FIG. 4A showing the results of observation ofa 64 μm×48 μm area with a Michelson-type phase-shifting interferencemicroscope, FIG. 4B showing a line distribution in the center of FIG.4A, FIG. 4C showing the results of observation with an AFM of a 500nm×500 nm area, and FIG. 4D showing a Raw profile of FIG. 4C;

FIG. 5A through 5D show the results of observation of a processing mark,FIG. 5A showing the results of observation with the Michelson-typephase-shifting interference microscope, FIG. 5B showing a linedistribution in the center of FIG. 5A, FIG. 5C showing an enlarged viewof the square area shown in FIG. 5A, and FIG. 5D showing a linedistribution in the center of FIG. 5C;

FIGS. 6A through 6D show the results of observation of the SiC wafersurface after processing, FIG. 6A showing the results of observation ofa 64 μm×48 μm area with the Michelson-type phase-shifting interferencemicroscope, FIG. 6B showing a line distribution in the center of FIG.6A, FIG. 6C showing the results of observation with the AFM of a 500nm×500 nm area, and FIG. 6D showing a Raw profile of FIG. 6C;

FIG. 7 is a graph showing the results of PSD analysis;

FIG. 8 is a graph showing comparison of the processing amount betweenSiC, Si and sapphire;

FIG. 9 is a schematic perspective view of a polishing apparatus;

FIGS. 10A and 10B show the surface state of a 4H—SiC (0001) samplebefore processing, FIG. 10A showing an X-slope profile and FIG. 10Bshowing a Raw profile;

FIGS. 11A and 11B show the surface state of the 4H-Di (0001) sampleafter flattening processing, FIG. 11A showing an X-slope profile andFIG. 11B showing a Raw profile; and

FIGS. 12A and 12B are conceptual diagrams illustrating transfer of theconfiguration or pattern of a base surface of a catalyst to a processingsurface of a workpiece, as effected by processing according to thepresent invention, FIG. 12A showing the processing surface beforeprocessing and FIG. 12B showing the processing surface after processing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference topreferred embodiments. The processing principle of the present inventionconsists in immersing a workpiece and a catalyst in a processingsolution, bringing the catalyst close to or into contact with theworkpiece, and processing the workpiece by an active species generatedfrom a molecule in the processing solution, adsorbed on the catalyst.

In particular, the catalyst-aided chemical processing method of thepresent invention comprises: immersing a workpiece in a processingsolution in which a halogen-containing molecule is dissolved, saidworkpiece normally being insoluble in said processing solution; andbringing a platinum, gold or ceramic solid catalyst close to or intocontact with a processing surface of the workpiece, thereby processingthe workpiece through dissolution in the processing solution of ahalogenide produced by chemical reaction between a halogen radicalgenerated at the surface of the catalyst and a surface atom of theworkpiece. Though the halogen-containing molecule preferably is hydrogenhalide, a molecule having such a chemical bond as C—F, S—F, N—F, C—Cl,S—Cl, N—Cl, or the like, can also be used.

An aqueous solution, in which a hydrogen halide molecule is dissolved,is herein referred to as hydrogen halide acid. Examples of the halogeninclude fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Sincethe chemical reactivity decreases with the increase in the atomicnumber, hydrofluoric acid (HF solution) or hydrochloric acid (HClsolution) is preferred as a processing solution for use in practicalprocessing.

Fluorine has the strongest chemical reactivity among non-metal elements,and directly reacts with almost all elements. Chlorine is chemicallyvery active, and reacts with water, organic compounds and many metals.When an HF solution or HCl solution is used as the processing solution,the material of the workpiece must be one which is normally insoluble inthe HF or HCl solution or one which has a solubility but is virtuallyinsoluble in the solution within the processing time.

A platinum, gold or ceramic solid catalyst, which promotes the reactionof oxidizing hydrogen and taking out hydrogen ion and an atom, is usedas the catalyst.

FIGS. 1A through 1C are conceptual diagrams illustrating processingaccording to the present invention. As shown in FIGS. 1A through 1C, aplatinum catalyst 1 is brought closed to or into contact with aprocessing surface 2 of a workpiece. Taking as an example the use of anHF solution as a processing solution, an HF molecule 20 in the HFsolution is dissociated into hydrogen ion 22 and an active F radical 24in the vicinity of the platinum catalyst 1 (see FIGS. 1A and 1B).Processing progresses through dissolution in the HF solution of ahalogenide 30 produced by chemical reaction between the F radical 24 andan atom 26 of the processing surface 2 (see FIG. 1C). At a point distantfrom the catalyst 1, an F radical 24 reacts with a hydrogen ion 22 toform an inactive HF molecule. The present catalyst-aided chemicalprocessing method can thus be a chemical processing method with whichprocessing progresses only beneath the base surface, i.e. the lowersurface of the catalyst 1.

The catalyst-aided chemical processing method of the present inventionhas the following characteristics: (1) A reactive species is producedonly on a base surface; (2) the reactive species becomes inactive whenit leaves the base surface; and (3) the physical properties of the basesurface do not change over a long period of time.

These characteristics of the present processing method offer thefollowing advantages: Since “a reactive species is produced only on abase surface”, unlike chemical etching, it becomes possible to process aprocessing surface of a workpiece without being influenced by the planeindex of the processing surface. Since “the reactive species becomesinactive when it leaves the base surface”, the base surface can betransferred to the processing surface. Accordingly, as with EEM,flattening of the processing surface at an atomic level can be expected.Furthermore, since “the physical properties of the base surface do notchange over a long period of time”, the processing surface does notchange even when the base surface is transferred and the processingprogresses. With such advantages, the present catalyst-aided chemicalprocessing method can be an efficient ultra-precision processing method.

In order to confirm the processing principle of the catalyst-aidedchemical processing method of the present invention, a processingapparatus for basic experiment was fabricated. FIGS. 2A and 2B showschematic views of the processing apparatus. A sample stage 4, providedwith a vertical rotating shaft, was provided at the bottom of aprocessing vessel 3, an SiC wafer 5 as a sample was fixed on the uppersurface of the sample stage 4, and a J-shaped bent platinum wire 7,mounted to the lower end of a support rod 6 and disposed above the Sicwafer 5, was brought into contact with the upper surface of the SiCwafer 5 such that the bend of the wire 7 makes point contact with aneccentric point in the upper surface of the SiC wafer 5. The processingvessel 3 was filled with an HF solution. Because of the use of HFsolution, those portions of the apparatus, which are to contact thesolution, are made of polytetrafluoroethylene (PTFE). Processing of thesample was carried out while rotating the sample stage 4 by a motor andcontinually supplying the HF solution to the processing site.

The processing conditions are shown in Table 1 below.

TABLE 1 Processing solution 50% HF solution Catalyst Pt Workpiece SiCRotational speed 1.6 rpm Processing time 300 min

The results of processing are shown in FIGS. 3A and 3B. FIG. 3A showssurface irregularities distribution including a ring-shaped processingmark observed under a Michelson-type phase-shifting interferencemicroscope, and FIG. 3B shows a line distribution along one diameter ofthe processing mark. The large sine curve in the line distributionindicates a surface undulation, and the distribution shows the formationof a step-like groove corresponding to the processing mark. The diameterof the processing mark was 9 mm, the processing depth was 40-100 nm, andthe processing amount per revolution was 0.08 to 0.21 nm/revolution. Ithad been confirmed that the wafer sample cannot be processed when thesample stage 4 is rotated in the same manner but before filling the HFsolution into the processing vessel 3.

The experiment shows that SiC, which is difficult to process by chemicaletching, can be easily processed by the present processing method.Further, since the wafer sample was processed only beneath the catalysthaving a base surface, the base surface is considered to have beentransferred to the processing surface of the sample. The experiment thusdemonstrates the effectiveness of the novel catalyst-aided chemicalprocessing method of the present invention.

FIGS. 4A through 6D show the results of observation of the SiC wafersurface, before and after processing, by the Michelson-typephase-shifting interference microscope and an AFM (atomic forcemicroscope).

FIGS. 4A through 4D show the results of observation of the SiC wafersurface before processing, FIG. 4A showing the results of observation ofa 64 μm×48 μm area with the Michelson-type phase-shifting interferencemicroscope, FIG. 4B showing a line distribution in the center of FIG.4A, FIG. 4C showing the results of observation with the AFM of a 500nm×500 nm area, and FIG. 4D showing a Raw profile of FIG. 4C.

FIG. 5A through 5D show the results of observation of the processingmark, FIG. 5A showing the results of observation with the Michelson-typephase-shifting interference microscope, FIG. 5B showing a linedistribution in the center of FIG. 5A, FIG. 5C showing an enlarged viewof the square area shown in FIG. 5A, and FIG. 5D showing a linedistribution in the center of FIG. 5C.

FIGS. 6A through 6D show the results of the same observation as FIGS. 4Athrough 4D of the square area shown in FIG. 5C. Thus, FIGS. 6A through6D show the results of observation of the processed portion afterprocessing of the SiC wafer, FIG. 6A showing the results of observationof a 64 μm×48 μm area with the Michelson-type phase-shiftinginterference microscope, FIG. 6B showing a line distribution in thecenter of FIG. 6A, FIG. 6C showing the results of observation with theAFM of a 500 nm×500 nm area, and FIG. 6D showing a Raw profile of FIG.6C.

The results of observation with the Michelson-type phase-shiftinginterference microscope show large irregularities on the SiC wafersurface after processing. This is considered to be due to transfer ofthe original surface irregularities upon the processing with theplatinum wire. This fact demonstrates transferability of a base surfaceaccording to the present invention and poses no problem becauseflattening is not under consideration at present.

FIG. 7 shows the results of PSD analysis of the AFM data on the SiCwafer surface, before and after processing, in the 500 nm×500 nm area.As can be seen from the results of PSD analysis, the SiC surface wasflattened by the processing in a space wavelength range of 10 nm to 100nm. Flattening can be expected also in an intermediate wavelength rangeand in a low-frequency range.

In order to examine what materials other than SiC can be processes,wafer samples of Si, sapphire, etc. were subjected to the sameprocessing experiment. The results are shown in FIG. 8. Since theabove-described processing apparatus is one adapted for basicexperiment, the diameter of a circular processing mark, contact betweenthe catalyst and a test sample, etc. can vary between samples tested,and therefore quantitative comparison of the processing amount betweensamples is difficult. However, qualitative comparison is possible.Accordingly, taking the processing amount per revolution in processingof SiC with the Pt catalyst as 1, the processing amount was evaluatedfor Si and sapphire. Further, the same processing experiment was carriedout but using an Au catalyst instead of the Pt catalyst, and the sameevaluation of the processing amount was conducted.

As is apparent from the results, Si can be processed more easily thanSiC. Sapphire also can be processed. The fact that sapphire can beprocessed indicates that the processing according to the presentinvention is not effected through oxidation.

FIG. 9 shows a schematic perspective view of a polishing apparatus. Thepolishing apparatus 10 includes a vessel 11, a rotatable platen 12,provided in the vessel 11, whose surface is composed of a materialhaving a catalytic action, such as Pt, and a holder 14 provided at thefront end of a rotating shaft 13 which is provided parallel andeccentrically to the axis of rotation of the platen 12. Further, thepolishing apparatus 10 is provided with a processing solutioncirculation system in which an HF solution as a processing solution isfilled into the vessel 11, the processing solution is recovered througha recovery pipe 16 while it is supplied from a supply pipe 15, therecovered processing solution is purified with a not-shown processingsolution purifier, and the purified processing solution is re-suppliedfrom the supply pipe 15. In operation, a workpiece is fixed to theholder 14 and the processing surface of the workpiece is brought closeto or into slight contact with the platen 12, and the processing surfaceis processed into a flat surface by rotating the platen 12 and theholder 14. It is possible to provide a net-like or spiral groovestructure in the surface of the platen 12 so that a fresh processingliquid can be supplied to the processing zone as the platen 12 rotates.

Flattening processing was carried out by using Pt as a surface materialfor the platen 12, a 10% HF solution as the processing solution, and4H—SiC (0001) as a processing sample. FIGS. 10A and 10B show the surfacestate of the sample before processing, and FIGS. 11A and 11B show thesurface state of the sample after processing. Flattening of theprocessing surface as shown in FIG. 11, i.e. removal of scratches andreduction in roughness, was attained in 30 minutes of processing.

As shown in FIGS. 12A and 12B, it is possible to utilize the lowersurface of a catalyst 31 as a processing base surface to transfer theconfiguration or pattern of the base surface to the processing surface32 of a workpiece. The Figures illustrate the case of forming a groove34, corresponding to the shape of the rectangular catalyst 31, in theprocessing surface 32 of the workpiece. A layer of catalyst, facing aprocessing surface, could sufficiently function as a processing basesurface. Accordingly, a film-forming technique, such as plating or vapordeposition, can be applied to form a processing base surface. When apattern is formed on the processing base surface of a catalyst, a raisedportion of the pattern can be transferred as a recess to the processingsurface of a workpiece. This could be utilized in the manufacturing ofsemiconductor devices.

Though not shown diagrammatically, it is also possible to use aprocessing tool comprising a synthetic resin base and a plating orcoating film of catalyst provided on a surface of the synthetic resinbase, a processing tool comprising a mixture of a synthetic resin baseand a powdery catalyst, with part of the powdery catalyst being exposedon a surface of the synthetic resin base, a processing tool comprising anon-woven fabric and a powdery catalyst carried in the interstices ofthe non-woven fabric, a processing tool comprising a non-woven fabriccomposed of fibers plated or coated with a catalyst, etc. Polishing orlapping of a processing surface of a workpiece can be carried out bymoving such a processing tool relative to the processing surface.

Further, it is possible to carry out similar processing to EEM bydispersing a powdery catalyst in a processing solution and supplying thepowdery catalyst to a processing surface of a workpiece with a flow ofthe processing solution. The processing solution, dispersed the powderycatalyst therein, can be supplied to the processing surface of theworkpiece by using supply means conventionally employed in EEM, inparticular a rotating ball or a high-pressure nozzle.

What is claimed is:
 1. A catalyst-aided chemical processing apparatusfor polishing an SiC wafer comprising: a rotatable platen including asynthetic resin base and a plating or coating film formed on thesynthetic resin, the plating or coating film having a processing basesurface consisting of a platinum, gold or ceramic solid catalyst; arotational shaft provided parallel and eccentrically to the axis ofrotation of the platen; a holder, provided at a front end of therotational shaft, for holding the SiC wafer and bringing a surface ofthe SiC wafer close to or into contact with the processing base surfaceof the platen while rotating the SiC wafer; and a processing solutionsupply portion for supplying a processing solution, in which ahalogen-containing molecule is dissolved, to between the processing basesurface of the platen and the surface of the SiC so that a halogenradical is generated at the processing base surface by dissociating thehalogen-containing molecule, wherein the processing solution supplyportion includes a vessel for holding the processing solution andimmersing the platen in the processing solution, and a supply pipe forsupplying the processing solution to the vessel.
 2. The catalyst-aidedchemical processing apparatus according to claim 1, wherein thehalogen-containing molecule is hydrogen halide, and the hydrogen halideis dissociated at the processing base surface to generate the halogenradical.
 3. The catalyst-aided chemical processing apparatus accordingto claim 2, wherein the hydrogen halide is hydrogen fluoride or hydrogenchloride.
 4. The catalyst-aided chemical processing apparatus accordingto claim 1, wherein the processing base surface has a net-like or spiralgroove structure.